1. Field of the Invention
The present invention relates to a copying apparatus that can form an image with a transparent toner.
2. Description of the Related Art
An electrophotographic copying apparatus can use a transparent toner to form a glossy image. An image formation technique discussed in Japanese Patent Application Laid-Open No. 5-265287 includes determining a non-text region of a document image having been read and forming an image of the detected non-text region with a transparent toner. Further, an image formation technique discussed in Japanese Patent Application Laid-Open No. 2007-034040 includes analyzing a document image having been read and forming an image of a photographic image region with a transparent toner without using the transparent toner for image formation of a presentation material region (e.g., graphs and drawings).
Further, an image formation technique discussed in Japanese Patent Application Laid-Open No. 2002-207334 includes determining a photo region based on a detection of the glossiness of a document and overlapping a transparent toner on the photo region. The technique discussed in Japanese Patent Application Laid-Open No. 2002-207334 includes a light emitting element that is capable of obliquely emitting light to irradiate the document with the emitted light and a light receiving element that is capable of receiving regular reflection light from the document. The light emitting element and the light receiving element are optical elements newly provided in addition to an image sensor that is capable of reading a document image.
The technique discussed in Japanese Patent Application Laid-Open No. 2002-207334 further includes comparing the quantity of light having been received by the light receiving element with a threshold and, if it is determined that the received quantity of light exceeds the threshold, identifying a detected region as a glossy region. However, in view of reducing the cost of the apparatus and reducing the size of the apparatus, the above-described conventional image formation technique is not desired because it requires both the light emitting element and the light receiving element that are newly provided for the purpose of detecting the glossiness of a document.